This site
is simply about the physics of rear bicycle suspension design.
We will go through the designs commonly seen on today's modern
bicycles, with special emphasis on (basic) static analysis
of each design with diagrams. We will discover some of the
advantages and disadvantage of each design and the kind of
style of riding they cater to.
First, a little bit of background:
Ever since the wheel was invented and attached to a vehicle, there has been an integral problem: uneven terrain. Rough terrain leads to limited contact of the wheel to the ground (and therefore less control), and harmful vibrations and wear on the vehicle. The solution to this problem may seem trivial. Just make the wheel move semi-vertically with reference to the vehicle it is attached to, right? Well, yeah, but how? This is the challenge that has motivated engineers for centuries to design new and clever ways to simply attach wheels to their vehicles.
Bicycles have been popular modes of transportation for almost two hundred years. Somewhere along the line about one hundred years ago, a clever engineer got the idea that he could make a lot of money if he designed some sort of suspension to make a smoother ride. The idea was lost as people weren't interested in the recreational aspect of cycling, and most rode on road anyway.
In and around fifty years ago, recreational off-road cycling boomed. This produced a massive demand for high-end bicycles and led to an entire industry being created. More companies spent more money on designing bicycle suspension and more efficient designs resulted. Suspension forks have only varied greatly with internal components and materials, but general appearance has been maintained. Rear suspension, however, has evolved virally.